Gates Carbon Drive CDX Belt – Black - 137T
The Gates Carbon Drive CDX Belt – Black is the strongest belt in the Gates range: a clean, oil-free carbon belt for touring, trekking, off-road, cargo and e-bikes with mid-drive motors up to 120 Nm. The all-black version of the CDX belt, in 20 lengths from 108 to 183 teeth.
Why choose the CDX belt?
No chain, no oil. No lubrication, no rust, and dirt rinses off with water. 
Built for hard use. Extra-reinforced carbon cords and a very wear-resistant polyurethane surface; Gates rates CDX at up to 4× the life of a chain. 
Strong enough for e-bikes. Rated for hub motors and for mid-drive motors up to 120 Nm. 
20 lengths. From 108 to 183 teeth, all 11 mm pitch and 12 mm wide.
CDX, CDC or CDN: which Gates belt is right for you?
Gates makes three belt lines with the same size and profile. CDX (this belt) is the strongest, for touring, off-road, cargo and mid-drive e-bike motors up to 120 Nm. CDC is the balanced choice for daily commuting and mid-drive e-bikes up to 75 Nm. CDN is the entry-level line for casual city riding.
Coming from a CDN or CDC belt? This is what CDX adds
Gates rates CDX at 4× the life of a chain – double CDN (2×) and one step more than CDC (3×) – with extra-reinforced carbon cords, a very wear-resistant polyurethane surface and a rating for mid-drive e-bike motors up to 120 Nm (CDC: 75 Nm). The belt has the same 11 mm pitch and 12 mm width, so you choose the same tooth count as before. For short, casual rides, CDN or CDC is still enough.
Black or blue: what the colour means
The standard CDX belt is black with blue tooth fabric, and this one is all black. The colour changes the look, not the size or the fit: both are CDX belts with the same 11 mm pitch and 12 mm width. On sprockets, “CDX:Black” means a black-coated steel sprocket – not a belt type – so belt and sprocket colours do not need to match.
No chain, no oil, no mess
A belt needs no lubrication, so there is no grease on your hands and clothes and no rust, and dirt and mud rinse off with water. The drive is virtually silent in most conditions. Just keep the tension right – the free Gates Carbon Drive app measures it by sound.
How the Gates belts compare
| CDX (this belt) | CDC | CDN | |
|---|---|---|---|
| Gates positioning | Top of the range | Mid-range | Entry level |
| Made for | Touring, trekking, off-road, cargo and all-year daily riding | Daily commuting, urban and trekking bikes, mid-drive e-bikes | Short, casual city rides and errands |
| E-bike motors | Hub motors and mid-drive up to 120 Nm | Hub motors and mid-drive up to 75 Nm | Hub motors |
| Rated life (Gates, compared with a chain) | 4× | 3× | 2× |
| Belt material | Polyurethane with extra-reinforced carbon cords, very wear-resistant | Ethylene elastomer with next-generation carbon cords | Polymer with carbon cords |
| Rear sprockets (Gates Europe data) | Aerospace stainless steel (silver) or black coated steel (CDX:Black) | Chrome-moly steel | Chrome-moly steel |
| Belt size | 11 mm pitch, 12 mm wide | 11 mm pitch, 12 mm wide | 11 mm pitch, 12 mm wide |
Frequently asked questions
Which belt length do I need?
It depends on your frame and sprockets: the distance between the crank and the rear axle, and the tooth count of the front and rear sprocket. Gates offers a free Center Distance Calculator in its Gates Sanity Check. Not sure? Send us your frame, hub and sprocket sizes and we will help you choose.
Can I use this belt on an e-bike?
Yes. Gates rates CDX belts for hub-motor e-bikes and for mid-drive e-bikes up to 120 Nm of motor torque.
Can I fit a CDX belt as an upgrade on my CDC or CDN setup?
Yes. A CDX belt has the same 11 mm pitch and 12 mm width as CDC and CDN belts, so you choose the same tooth count as before, and Gates Europe lists it as combinable with all CDX, CDC and CDN sprockets. Your existing sprockets keep their own rating, so for the toughest setup choose CDX sprockets as well.
What do CDX, CDC and CDN mean, and what is CenterTrack?
They are Gates’ three belt lines for bicycles: CDX (top), CDC (mid-range) and CDN (entry level). All use CenterTrack: a groove in the middle of the belt’s teeth runs on a guide in the centre of the sprocket, so the belt cannot run off. The older ST (SideTrack) range is separate and does not fit CenterTrack parts.
How tight should the belt be?
Correct tension matters. Too loose and the belt can skip teeth; too tight and it loads the hub bearings. Measure it with the free Gates Carbon Drive app, which listens to the belt, or with a Gates Krikit gauge (the “CDS Krikit” with the blue plastic).
Does a belt need lubrication, and how do I handle it?
Never lubricate a Gates belt. If it squeaks in very dry or muddy conditions, rinse the drivetrain with water. Do not twist, back-bend, crimp, invert, bundle or zip-tie the belt, and never pry it onto the sprockets – damage to the carbon cords is the most common reason for a belt to fail.
Sizes and Gates part numbers
Find your belt by its tooth count. The Gates article number and type designation are printed on the back of the belt, so you can match a replacement exactly.
| Teeth | Gates article no. | Gates type designation |
|---|---|---|
| 108T | 9255-00962 | 11M-108T-12CT BLACK GACD |
| 111T | 9255-00948 | 11M-111T-12CT BLACK GACD |
| 113T | 9255-00899 | 11M-113T-12CT BLACK GACD |
| 115T | 9255-00911 | 11M-115T-12CT BLACK GACD |
| 118T | 9255-00913 | 11M-118T-12CT BLACK GACD |
| 120T | 9255-00898 | 11M-120T-12CT BLACK |
| 122T | 9255-00893 | 11M-122T-12CT BLACK |
| 125T | 9255-00915 | 11M-125T-12CT BLACK GACD |
| 128T | — | 11M-128T-12CT BLACK GACD |
| 130T | — | 11M-130T-12CT BLACK GACD |
| 132T | 9255-00982 | 11M-132T-12CT BLACK GACD |
| 137T | — | 11M-137T-12CT BLACK GACD |
| 143T | 9255-01110 | 11M-143T-12CT BLACK GACD |
| 151T | 9255-01083 | 11M-151T-12CT BLACK GACD |
| 158T | 9255-01052 | 11M-158T-12CT BLACK GACD |
| 166T | 9255-01054 | 11M-166T-12CT BLACK GACD |
| 168T | 9255-01056 | 11M-168T-12CT BLACK GACD |
| 174T | 9255-01077 | 11M-174T-12CT BLACK GACD |
| 178T | 9255-01273 | 11M-178T-12CT BLACK GACD |
| 183T | 9255-01275 | 11M-183T-12CT BLACK GACD |
About Gates Carbon Drive
Gates Corporation has been a global leader in power transmission and belt drive technology since 1911. In 2007 it launched the first belt drive system for bicycles, and today more than 1,000 bike brands worldwide use Gates Carbon Drive, from city and trekking bikes to e-bikes, cargo and mountain bikes.
On the bike
